Abstract

Dynamic friction force microscopy is a valuable tool for the investigation of friction properties on the nanometer scale. The measuring technique is based on a longitudinal tip-sample modulation, leading to bending cantilever oscillations. A lock-in detection scheme is used to determine the lever response amplitude as a measure of the longitudinal tip-sample interaction. Here, we present an approach which monitors the resonance frequencies of the cantilever during an off-resonance sample modulation. Our experiments and simulations indicate that this oscillation behavior changes characteristically with increasing modulation amplitude at the static-to-sliding transition and can be used as an imaging technique.